Fair enough. I let a guy who is not a professional work on it. I can accept that opinion. In order to save money and quite frankly afford to drive the car I am stuck with back yard mechanics.

 

Stock GM 3/8 manifold bolt broke off after it bound up and got stuck snapped off in the aluninum.

 

you still have not verified that the bolt broke off in the head as I ask, or did it strip the threads on the head? It really makes no difference I guess.

Just some friendly advise, and take it for what its worth. I can tell you from my experience, if I did not do the majority of the work on my car and had to pay for it, I would sell it. The car is 20-25 years old, and vettes are not known to be the most reliable vehicles anyways. Labor will eat you alive on a car of this age.
If you are not going to turn wrenches and you want a vette, find a low mileage c5 or c6 and don't modify it. If power is important find a z06. The c5 z06 will pretty much run with most Head and Cam stock bottom end C4's Of course the C6 Z06 is even better.
Again, its rare that you will find anyone who will give a warranty on a modified car.

 

Quote:

Originally Posted by C4in mesa

Stock GM 3/8 manifold bolt broke off after it bound up and got stuck snapped off in the aluninum.

OK you posted this while I was writing the other message.

So you used the stock bolts? You did not use header bolts? That may explain it, that it broke off. 25 years of heat will rust those things off. Don't know on a L98, but on a LT1 I don't think you could even do this. The flange is too thick Guess the next question is, who supplied parts?

 

If that bolt is like my 85, it's a like a stud and is used to attach brackets. If it bound up when trying to remove it the threads in the head were probably damaged. I'm also guessing they tried to just chase the threads with a tap and it didn't take the torque. If it were me I'd be looking for a way to drill it and install a helicoil.

 

The elephant in the room was refering to when I'm around Greg these days. He knows he screwed up he knows he forgot to put the correct bolts in the header. If he had done his job right none of this would have happened. The popular opinion seems to be I was a fool for not paying $3,000 to have my engine pulled and then installed. I saved money and it cost me. The transmission shop said that the leak was caused by whoever installed the motor. He is the one who pulled it off and fixed it for $200. Never had he seen a brand new pump seal spring come off.

 

Pictures are on my profile of the bolt. It is in the center holding the A/C condensor support bracket.

 

This new guy wants to drill 10mm right through the old hole and install a 10mm stud. Then use a nut to tighten itself to the head rather than Helicoil. He thinks the gasket is still good. If it doesnt work then the header has to come off. Why some guys think the head has to come off is unknown ?

 

The reason for pulling the head is to get access for a drill and tap. A 10mm is slightly larger than a 3/8. It's worth a try but don't be surprised if you end up pulling the header and installing a helicoil.

 

At this point I have nothing to lose. If it works then its fixed. If not remove the header and weld it. It is in the middle if you aren't familiar where the A/C support bracket goes. Pretty straight on. It is why Greg just ran a drill through the broken bolt and tapped it. That fix didn't last

 

You've already done something "oversize" in the first attempt I would think if the original bolt was just drilled out or maybe I guess you tried to save the 3/8 thread. I would guess that would have been the 10mm already. .375 is 9.52mm - you can try all you like but I believe if the cars worth anything then it deserves the cylinder head be pulled and the repair done properly.

It seems you're determined to attempt something so you might as well "have at it"! Why bother asking -

 

This pretty much sums up the situation, and pretty good advice.

 

you need that antiseize on steel or stainless threading into aluminum

 

I think you may be looking at it the wrong way - you said it was rebuilt last year. So it probably is at least one year since the installation. Any shop that installed the engine probably wouldn't warranty the installation for more than 6 months, maximum a year. I say let it go.

 

If I've learned anything in seven years of daily driving a C4, it is that to take a short cut to save a little money now, winds up costing alot more money in the long run. Do it once, do it right, and don't worry later. I really think that you might be headed for trouble doing what you propose. What if that bigger drill bit hits a coolant tube or something crazy like that. At the very least, how long will that 10mm bolt hold tight.

I would have used a bolt extractor in the first place.

 

I originally came at this thinking it best to clean the hole of any pieces of the old bolt. Pure aluminum. Weld it and start with a brand new hole. I do agree about the "do it right once" If I had insisted on that in the beginning I would not have an exhaust leak today. The reason why I started this thread was to get an idea about the whole situation regarding the cause of this problem. I paid someone who isn't a professional to do the job. A mutual friend of Greg and I told me last night let Greg do brakes, tune ups, radiator flushes and other simple things that don't involve large amounts of time and money. That way you can be assured the job will be done right. I'M 43 years old and I am not going to start buying tools and teach myself how to turn a wrench. Greg must have $30K tied up in his tools over the last 20 years. I was upset at the whole situation and really expected my friend to say he was sorry. When he took sand paper to my Targa top to remove a scratch and ruined it he said he was sorry. Not this time however !! On here for the most part I get pragmatic advice and rational advice. Back yard mechanic's take your chances PERIOD. I needed to hear that. Next Monday I am going to drop my car off to another back yard mechanic. He is a retired Chevy dealership mechanic and has lots of experience with modified engines and headers. I was referred by owners who take their car to him no complaints. This time however I understand the chances and risks better.

 

The way to repair a stripped header bolt hole in the head is to insert a helicoil. I don't think anyone would fill the hole and retap it. If the header gasket is leaking, it should be replaced because it's probably blown out.

 

agree with this. whether the head comes of or not is purely if access can be gained to do on car or has to come off for room.

would be cautious welding on any head and only as a last resort

doing on will save time and labor

off will mean new head and manifold gasket as well increase the chance some thing else can be disturbed or broken. wiring plugs ect.

 

There's no short-cut to a "proper" repair. To do a repair that will last is going to require the head "off the car" - this particular car for sure needs the head removed. Can it be done on the car? Doubt it and there's no doubt I'd say that the head will come off eventually for a correct repair OR it's entirely possible maybe it won't ever get "repaired" - "patched maybe" but repaired likely NOT!

In the end "time and labor" will exceed or maybe double after the attempt to "patch"!

 

C4,

This is a no win situation for both YOU and Greg...

if he messed the repair up in the first place, I wouldn't count on his expertise to figure it out now...

What I WOULD do, is get him alone someday and just ask him if he will help you out on some OTHER repairs since HE was the one that used the wrong bolts and started this mess...Just tell him that you're OUT of MONEY due to the EXTRA expense from this goof up with the bolts..
He admitted that he used the wrong bolts.... When he is confronted (cornered) in this way, no-threatening and civil, he has little choice but to agree to SOME amount of compensation. In more common terms, this technique of getting somebody to step up reluctantly, is called "guilting them into it". He will respond because he feels guilty about what he did.
Future oil changes, doing your brakes at No Charge...something to "make it right".

Saying 'sorry'....probably ain't gonna happen until you corner him and pull it out, and when you have to DIG for an apology its not nearly as gratifying as one that came to you on its own.

The relationship can probably be saved, That's why you use GUILT to motivate instead of anger or pressure. Just keep telling him how hard this is on you financially and that this just wasn;t EVER part of the budget. Now you're out of money for the project and having to spend the rent money to get it fixed...(exaggerations are allowed, just don't go TOO far...) Guilt will do the rest. IF it does not work, then the guy needs to be forgotten anyway. I've fired many a friend and lost their number when or if I discovered that they were doing some really shiddy things to people without remorse. Good people don;t take advantage and they ACCEPT responsibility for their actions. Only a$$holes dodge responsibility. Nobody needs another a$$hole. 1 is enough.

This needs to be handled and forgotten about asap. The longer it waits the harder it is to move on.

The 10mm hole & tap is probably the best plan for an "in-car" repair that's solid. Next time the heads come off or the eng out, you can explore other options. For now, drill & tap. I'd try to drill & tap the 3/8 to see IF that can be saved...might be a minimal bit of bolt in there. See what comes out,. TRY the stock size tap and IF it bites in, use the 3/8 header bolt OR a longer stud. If you have to go to 10mm...its not the end of the world. As long as the repair is solid and has no gray tape involved.

Good luck buddy !